William m



(No Model.)

W. M. THOMAS.

GUT-OUT FOR ELECTRIC LAMPS.

No. 312,529. Patented Feb. 17,1885.

WITNESSES v I INVENTOR William M. Thomas. %6L, 3

By his Attorneys N, FETERs Phnlo-Utho n hen Washington. 0. c.

UNIT D STATES PATENT OFFICE.

VILLIAM M. THOMAS, OF GRAND RAPIDS, MICHIGAN, ASSIGNOR OF ONE- HALF TO THE GRAND RAPIDS ELECTRIC LIGHT AND POWER COMPANY,

OF SAME PLACE.

I CUT-OUT FOR ELECTRIC LAMP S.

SPECLI E'ICATION forming part ofLetters Patent No. 312,529. dated February 17, 1885. Application filed April fl, 1894. (X model.)

T 0 all whom it may concern.-

Be it known that I, WILLIAM M. THOMAS, of Grand Rapids, in the county of Kent and State of Michigan, have invented certain new and useful Improvements in Automatic Switches for Electric Lights, of which the following is a specification.

W'hen electric lamps are connected in series,

they are usually provided with some automatic IO devices forfeeding the carbon and maintaining the arc interval between the electrodes. This automatic adjustment, however, may in some cases failto properly act, and the carbons in burning away may produce an excess 1 of arc length,which would not only monopolize electric energy at that point in the circuit, but the excessive length of the are would be more or less destructive to the lamps, and might endanger the surroundings. The breaking of the carbon also sometimes produces a rupture in the lamp sufficient to open the circuit.

The object of my invention is to provide an automatic cut-out for an arc lamp, the carbon points or electrodes of which are automatically my improved cut-out are illustrated in the ac-- companying drawing, which is a diagram view showing the essential features of the invention.

The main circuit is indicated by'the full line L, in which the current flows in the direction 40 indicated by the arrow to the carbon of the lamp. The line from the opposite or carbon is indicated by dotted lines, the direction of the current still being shown by the arrow. The two sections of the line which approach 5 and leave the lamp are wound parallel and in the same direction around asot't-iron core, A, as clearly shown in the drawing. The usual shunt or branch circuit, 8, containing a coil, B, of relatively high resistance, is thrown around the electrodes of the lamp, starting at the conductor indicated by the full line before it enters the i carbon, and connecting with the line indicated by dotted lines at some suitable point after it leaves the core A. Under this condition of the circuit and connec- '55 tions, upon the failure or interruption of the circuit at the electrodes of the lamp, the continuity of the circuit will be maintained through the shunt s, and the cut-out will instantaneously be operated to effectually shunt the current from the lamp, as follows: Asuitable armature, B, is arranged opposite the end of the soft-iron core A. This armature is carried upon a spring, C, which is mounted on a suitablesupport, and may be provided with any ordinary adjusting devices. The spring 0 and armature B are electrically connected with the circuit indicated by the full line at the point so, while the core A is connected with the circuit indicated by the dot- 7o ted line at the point 3 It is obvious, therefore, that when the armature is drawn into contact with the magnet A a supplementary shunt passing from x through 0 BA and the line Z will be completed around the electrodes of the lamp. This shunt is thrown into operation in the following manner: As the two branches of the main line L are wound paral; lel and in the same direction on the core A, and as the current passes in opposite direc- 8o tions through them, the efi'ectis that they neutralize each other more or less. The spring 0 may be adjusted, however, so that when the resistance between the electrodes caused either by the increase in the length of the are or the 8 5 rupture of the circuit is so great that electromotive force in the dotted line running around the core A is reduced to a given amount, the excess of current in that part of the circuit indicated by the full line will energizethe core 0 A with such a power that the armature B will be attracted, and the supplementary shunt above described will be completed. The amount of current diverted from the dotted line which surrounds the core through the shunt s will be, generally speaking, proportional to the length of the are. It is obvious, therefore, that by adjusting the armature B the device may be made to cut out whenever the are ex ceeds any given limit in length.

A suitable resistance, Rh, which may be adjustable, may be placed in the line Z. Should the carbon points, therefore, be brought together aftera rupture, or after the lamp has been cut out, a sufficient amount of the current would pass through the electrodes of the lamp to overcome or neutralize the magnetic energy of the core A. The armature B would therefore be drawn back out of contact with the core A, thus opening the shunt-circuit and permitting the normal passage of the current through the main circuit, as before described, thereby causing the automatic relighting of the lamp.

I have represented my improved devices in diagrammatic form; but the construction and operation will of course be clear to any one familiar with the subject of electricity; and it is obvious that the construction may be varied without departing from the principle of the invention.

I am aware that it has heretofore been proposed to organize electric lamps with the carbons in a branch of the main line, and shunted by high and low resistance shunts, for the purpose of regulating the light and controlling the movement of the carbonsuch as shown, for instance, in the patent of Rain, No. 300,483, dated June 17, 1884. I do not, therefore, claim such subject-matter, but limit myself to the peculiar characteristics of my invention set forth in the claims.

I claim as my invention- 1. The combination, substantially as set forth, of a main line, the carbons of an electric lamp placed in a loop of the main line. an electro-magnet or core which is wound with both legs or branches of the loop in which the lamp is placed, an armature for said magnet, and a shunt-circuit which is automatically completed by the attraction of said armature when the arc length or-resistance in the lamp exceeds a certain limit.

2. The combination, substantially as set forth, of a main line, the carbons of an electric lamp placed in a loop ofthe main line, an electro-magnet or core which is wound with both legs or branches of the loop in which the lamp is placed, an armature for said magnet, a shunt-circuit which is completed by the attraction of said armature, a suitable'r'esistance in said shunt-circuit, and a second ordinary shunt-circuit of relatively high resist ance, for the purpose set forth.

3. The combination, substantially as set forth, of a main line, the carbons of an electric lamp. placed in a loop of the main line, an electro-magnet or core which is wound with both legs or branches of the loop, an armature for said magnet, a shuntcircuit which is completed by the attraction of said armature, and a resistance in said shunt-circuit.

4. The combination, substantially as set forth, of a main line, the carbons of an electric lamp placed in a loop of the main line, a shunt around the lamp, electromagnetic cut-out devices included in both legs of the main line loop for completing the shunt when the arc length of resistance of the lamp has been abnormally increased, and means for adjusting the cut-out devices to act at a given length of arc in the lamp.

In testimony whereof I have hereunto subscribed my name.

XVILLIAM M. THOMAS.

Witnesses:

XVM. H. Pownns, J. H. hlIARSl-IALL. 

